bgpd: new show cmd - bgp l2vpn evpn route vni all detail
This command is added to provide detailed information. It will be
useful in troubleshooting as we will be able to dump all detailed info
using a single command.
"net show bgp evpn route vni <all|id> [detail]". Additional filtering
can be done by providing vtep ip.

Command will display the detailed content for all vni and macs as
displayed by "net show bgp evpn route vni <> mac <> ip <>" for a single
vni, mac, ip.